NCAM: A surface marker for human small cell lung cancer cells

Abstract

Immunocytochemical and immunochemical techniques were used to study the expression of the neural cell adhesion molecule (NCAM) by human lung cancer cell lines. Intense surface staining for NCAM was found at light and electron microscopic levels on small celliung cancer cells. The NCAM polypeptide of M r 140000 (NCAM 140) was detected by immunoblotting in all of 7 small celliung cancer celllines examined and in one out of two of the closely related large cell cancer cell lines: it was not detected in cell lines obtained from one patient with a mesothelioma, in two cases of adenocarcinoma, nor in two cases of squamous cell cancer. In contrast, neuron-specific enolase was found by immunoblotting in all the lung cancer celliines tested and synaptophysin in all but the adenocarcinoma celliines. These antigens were localized intracellularly. The specific expression ofNCAM 140 by human small and large celliung carcinomas suggests its potential as a diagnostic marker.Lung cancer; Neural cell adhesion molecule; Marker